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I am having issues with my engine where I show #2,3,4,5 cylinders at zero PSI and #1 and 6 at 60 and 55 @PSI. I assume I need a new head gasket so I am wondering what the bolt nuts torque would be to the engine. The gasket I ordered is coming from Olson's gaskets and is copper.

It is a 6 cylinder 533.

Thanks for your guidance.

Gar

Try putting some 30 weight oil in the plug holes of the cylinders with no pressure,replace the plugs and crank the engine a bit again and let it sit for a while. Recheck the pressure. Valves could be sticking. We had a similar situation on a 36 business coupe with an 8 cylinder. Three cylinder registered no pressure but after putting in a bit of oil they all came back within 20 pounds of each other. Worth a try.

Regarding torque on the head bolts, I believe 60psi is recommended.

foot-pounds, or lb-ft, not psi. Yes, 60-62 foot-pounds would be appropriate for 7/16-20 threads.

Thank you. Once I receive the new gasket I will install it and secure it to 60lbs.

I tried oil and Marvel neither one helped. Head gasket here I come.

Thanks again for the input. It is much appreciated.

Gar

Be sure to torque them down after you've taken some runs. Check every 50-100 miles for a little while. Mark Lambert told me also that once you've torqued them, and are in the "checking" stage, to loosen them slightly, before torquing them tight again. This is especially required if you've replaced the studs.

My understanding is that when tightening down the nuts, I should start in the middle and center of the engine and work outward. Is there a recommended pattern that I should follow?

Gar

I would use the pattern shown in the 1954 manual for inspiration.

For this bolt pattern, a Y shape in the center, then the center row from middle out one way then the other way, then alternately the outer sides from middle out one way, then the other way.

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For something more similar to your motor, you could model from the below which is the Packard recommended sequence for a later 6-cylinder engine.

Source: Motor's Manual

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A word of caution regarding the head nut tightening torque for a 5th Series Six. I have a 533 Six and whilst Dave (Owen Dyneto) is correct that 60-62 ft lbs is appropriate for the 7/16 20 TPI threads, in my experience, I would suggest that unless your Torque Wrench is new or has been calibrated or checked in the past few years, or you have had new studs put into the engine, I would probably limit the torque to 55 ft lbs. If the studs are originals I have seen quite a number of corroded studs, particularly if the engine has been run without any corrosion protection for many years. It is a very bad feeling when a stud yields and you are looking for helicoils, etc. And as West Peterson advises the torque should be checked a number of times. Peter T .